Hydranautics ESPA 4-4040 Home / Shop Hydranautics ESPA 4-4040 $395.00 Home / Shop Hydranautics ESPA 4-4040 $395.00 Model Number: Hydranautics-ESPA-4-4040 Maximum quantity exceeded Minimum purchase amount of 0 is required Maximum purchase amount of 0 is allowed Call 928-830-8974 for more info... 10000000 Categories: Reverse Osmosis Membranes Manufacturer: Hydranautics Description Typical operating pressure of only 700kPa @ 25°C & 500ppm TDS. Elements feature male end connections.